Question 1

The free energy for the oxidation of glucose to CO₂ and water is -686 kcal/mol, and the free energy for the reduction of NAD⁺ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Accepted Answer

A)   Most of the free energy available from the oxidation of glucose is used in the production of ATP in glycolysis.
B)   Glycolysis is a very inefficient reaction, with much of the energy of glucose released as heat.
C)   Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis.
D)   There is no CO₂ or water produced as products of glycolysis.

Question 2

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?

Accepted Answer

A)   active transport
B)   allosteric regulation
C)   a reaction with a positive ΔG
D)   coupling of an endergonic reaction to an exergonic reaction

Question 3

Which of the following events takes place in the electron transport chain?

Accepted Answer

A)   the breakdown of glucose into six carbon dioxide molecules
B)   the breakdown of an acetyl group to carbon dioxide
C)   the harnessing of energy from high-energy electrons derived from glycolysis and the citric acid cycle
D)   substrate-level phosphorylation C

Question 4

The enzyme phosphofructokinase (PFK)  catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Given its critical role in glycolysis, which of the following conditions would be a likely consequence for dogs afflicted with this disorder?

Accepted Answer

A)   They would die as embryos.
B)   They would have elevated blood-glucose levels, which may result in a high incidence of diabetes.
C)   They would be lethargic and readily tire from exercise.
D)   They would carry out elevated levels of oxidative phosphorylation.

Question 5

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Accepted Answer

A)   He or she has to sit down and rest.
B)   Catabolic processes are activated that generate more ATP.
C)   ATP is transported into the cell from the circulatory system.
D)   Other cells take over, and the muscle cells that have used up their ATP cease to function.

Question 6

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

Accepted Answer

A)   oxidation of glucose and other organic compounds.
B)   flow of electrons down the electron transport chain.
C)   H⁺ concentration gradient across the membrane holding ATP synthase.
D)   transfer of phosphate to ADP.

Question 7

What happens when electrons are passed from one atom to a more electronegative atom?

Accepted Answer

A)   The more electronegative atom is reduced, and energy is released.
B)   The more electronegative atom is reduced, and energy is consumed.
C)   The more electronegative atom is oxidized, and energy is consumed.
D)   The more electronegative atom is oxidized, and energy is released.

Question 8

Carbon dioxide (CO₂)  is released during which of the following stages of cellular respiration?

Accepted Answer

A)   glycolysis and the oxidation of pyruvate to acetyl CoA
B)   oxidation of pyruvate to acetyl CoA and the citric acid cycle
C)   oxidative phosphorylation and fermentation
D)   fermentation and glycolysis

Question 9

Beta oxidation generates substrates for cellular respiration through which of the following processes?

Accepted Answer

A)   catabolism of glucose
B)   catabolism of glycogen
C)   catabolism of proteins
D)   catabolism of fatty acids

Question 10

Energy released by the electron transport chain is used to pump H⁺ ions into which location in eukaryotic cells?

Accepted Answer

A)   cytoplasm adjacent to the mitochondrial outer membrane
B)   mitochondrial inner membrane
C)   mitochondrial intermembrane space
D)   mitochondrial matrix

Question 11

If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Accepted Answer

A)   8
B)   12.5
C)   16
D)   25

Question 12

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?

Accepted Answer

A)   reduction of NAD⁺ to NADH
B)   reduction of FAD to FADH₂
C)   oxidation of NADH to NAD⁺
D)   hydrolysis of ATP to ADP +  ᵢ C

Question 13

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

Accepted Answer

A)   The pH of the matrix increases.
B)   ATP synthase pumps protons by active transport.
C)   The electrons gain free energy.
D)   NAD⁺ is oxidized.

Question 14

In chemiosmosis, what is the most direct source of energy that is used to convert ADP +  ᵢ to ATP?

Accepted Answer

A)   energy released as electrons flow through the electron transport chain
B)   energy released from substrate-level phosphorylation
C)   energy released from movement of protons through ATP synthase, down their electrochemical gradient
D)   energy released as electrons are transported across the inner mitochondrial membrane

Question 15

What kinds of cells carry out ATP synthesis by chemiosmosis?

Accepted Answer

A)   all cells, both prokaryotic and eukaryotic, exclusively using oxygen as the electron acceptor
B)   only animal cells in mitochondria, exclusively using oxygen as the electron acceptor
C)   only eukaryotic cells, both plant and animal, using either oxygen or other electron acceptors
D)   all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors

Question 16

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Accepted Answer

A)   It allows for an increased rate of glycolysis.
B)   It allows for an increased rate of the citric acid cycle.
C)   It increases the surface for oxidative phosphorylation.
D)   It increases the surface for substrate-level phosphorylation.

Question 17

High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of ________.

Accepted Answer

A)   competitive inhibition
B)   allosteric regulation
C)   the specificity of enzymes for their substrates
D)   positive feedback regulation B

Question 18

An organism is discovered that thrives in both the presence and absence of oxygen. Interestingly, as oxygen is removed from the organism's environment, the rate of sugar consumption increases while the growth rate decreases. What do these observations suggest about the likely identity of this organism?

Accepted Answer

A)   It is an unremarkable eukaryotic organism.
B)   It is a photosynthetic organism.
C)   It is an obligate anaerobic organism.
D)   It is a facultative anaerobic organism.

Question 19

Use the following information to answer the question below.

The citric acid cycle.
If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production?

Accepted Answer

A)   There would be no change in ATP production, but the rate of carbon dioxide production would increase.
B)   The rates of ATP production and carbon dioxide production would both increase.
C)   The rate of ATP production would increase, but the rate of carbon dioxide production would decrease.
D)   The rates of ATP and carbon dioxide production would both decrease.

Question 20

Water is one of the end products of aerobic respiration. What is the source of the oxygen atom used in formation of the water?

Accepted Answer

A)   carbon dioxide (CO₂) 
B)   glucose (C₆H₁₂O₆) 
C)   molecular oxygen (O₂) 
D)   pyruvate (C₃H₃O₃⁻)

Exam 9: Cellular Respiration and Fermentation

The free energy for the oxidation of glucose to CO₂ and water is -686 kcal/mol, and the free energy for the reduction of NAD⁺ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Correct Answer
verified

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?

Correct Answer
verified

Which of the following events takes place in the electron transport chain?

Correct Answer
verified
C

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Given its critical role in glycolysis, which of the following conditions would be a likely consequence for dogs afflicted with this disorder?

Correct Answer
verified

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Correct Answer
verified

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

Correct Answer
verified

What happens when electrons are passed from one atom to a more electronegative atom?

Correct Answer
verified

Carbon dioxide (CO₂) is released during which of the following stages of cellular respiration?

Correct Answer
verified

Beta oxidation generates substrates for cellular respiration through which of the following processes?

Correct Answer
verified

Energy released by the electron transport chain is used to pump H⁺ ions into which location in eukaryotic cells?

Correct Answer
verified

If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Correct Answer
verified

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?

Correct Answer
verified
C

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

Correct Answer
verified

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + ᵢ to ATP?

Correct Answer
verified

What kinds of cells carry out ATP synthesis by chemiosmosis?

Correct Answer
verified

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Correct Answer
verified

High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of ________.

Correct Answer
verified
B

Correct Answer
verified

Use the following information to answer the question below. The citric acid cycle. If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production?

Correct Answer
verified

Water is one of the end products of aerobic respiration. What is the source of the oxygen atom used in formation of the water?

Correct Answer
verified

Exam 9: Cellular Respiration and Fermentation

The free energy for the oxidation of glucose to CO₂ and water is -686 kcal/mol, and the free energy for the reduction of NAD⁺ to NADH is +53 kcal/mol. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?

Correct AnswerverifiedShow Answer

The synthesis of ATP by oxidative phosphorylation, using the energy released by movement of protons across the membrane down their electrochemical gradient, is an example of which of the following processes?

Correct AnswerverifiedShow Answer

Which of the following events takes place in the electron transport chain?

Correct AnswerverifiedC

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. About 10% of Springer spaniels suffer from canine PFK deficiency. Given its critical role in glycolysis, which of the following conditions would be a likely consequence for dogs afflicted with this disorder?

Correct AnswerverifiedShow Answer

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply?

Correct AnswerverifiedShow Answer

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

Correct AnswerverifiedShow Answer

What happens when electrons are passed from one atom to a more electronegative atom?

Correct AnswerverifiedShow Answer

Carbon dioxide (CO₂) is released during which of the following stages of cellular respiration?

Correct AnswerverifiedShow Answer

Beta oxidation generates substrates for cellular respiration through which of the following processes?

Correct AnswerverifiedShow Answer

Energy released by the electron transport chain is used to pump H⁺ ions into which location in eukaryotic cells?

Correct AnswerverifiedShow Answer

If a cell is able to synthesize 30 ATP molecules for each molecule of glucose completely oxidized to carbon dioxide and water, approximately how many ATP molecules can the cell synthesize for each molecule of pyruvate oxidized to carbon dioxide and water?

Correct AnswerverifiedShow Answer

Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?

Correct AnswerverifiedC

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

Correct AnswerverifiedShow Answer

In chemiosmosis, what is the most direct source of energy that is used to convert ADP + ᵢ to ATP?

Correct AnswerverifiedShow Answer

What kinds of cells carry out ATP synthesis by chemiosmosis?

Correct AnswerverifiedShow Answer

In liver cells, the inner mitochondrial membranes are about five times the area of the outer mitochondrial membranes. What purpose must this serve?

Correct AnswerverifiedShow Answer

High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location from the active site. This is an example of ________.

Correct AnswerverifiedB

Correct AnswerverifiedShow Answer

Use the following information to answer the question below. The citric acid cycle. If you were to add one of the eight citric acid cycle intermediates to the culture medium of yeast growing in the laboratory, what do you think would happen to the rates of ATP and carbon dioxide production?

Correct AnswerverifiedShow Answer

Water is one of the end products of aerobic respiration. What is the source of the oxygen atom used in formation of the water?

Correct AnswerverifiedShow Answer

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C

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C

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B

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